The purpose of this clinical research center is to advance our understanding and treatment of individuals with speech motor disorders. We are in the process of achieving this objective through an integrated series of projects involving intelligibility, acoustic, aerodynamic, electromyographic, movement and force measures, in many studies observed simultaneously for critical comparative interpretations. More specifically, our research program involves four major areas of concurrent focus: (1) intelligibility, acoustic, and aerodynamic analyses of dysarthric speech, (2) the development of physiological profiles of speech motor sub-system impairments, (3) systems physiology-based investigations directed at the neural substrates of speech motor function and dysfunction, and (4) development, evaluation, and refinement of improved techniques for rehabilitation of speech motor disorders. In this proposed research period the program emphasis is upon dysarthric speakers with cerebellar disease or degeneration, spastic/athetoid cerebral palsy, and Parkinson's disease.